Eyewear is believed to have been developed in Europe and China during the thirteenth century. It is also believed that primitive man used shields made from bone and/or wood to protect their eyes from sun and wind. Primarily, eyewear was developed for functional reasons, namely to improve the wearer's vision and to protect their eyes from environmental elements. As time passed, eyewear as a fashion accessory became common.
Eyewear has many basic components and generally accepted terminology. Frames, primarily made of plastic, metal, or the like, are provided for holding lenses positionable in close proximity to the eyes of the wearer. A bridge, which is typically integral with the frame, typically rests on the wearer's nose and provides a natural resting spot for the frame. A hinge may be mounted to the frames at each side and temples, which are proximal the wearer's head, extend from the other side of each hinge. Earpieces may extend downwardly from the temples near the wearer's ears to further secure the eyewear.
The frame, which holds the lenses that correct or otherwise alter the wearer's vision, includes a frame front. The two temples may be replaced with a single strap that goes around the head such as used in goggles. New advances in materials, memory metals in particular, permit the replacement of a traditional hinge with a continuous structure and suggest that the term “joint” may be used instead of hinge. Indeed, the term “joint” may also be more appropriate for eyeglasses employing a strap instead of temples. The frames provide a frame cavity, which may also be referred to as an aperture, to carry a lens. The left lens is typically referred to as ocular sinister (OS) and the right lens is typically referred to as ocular dexter (OD).
Currently in the eyewear industry, frames are designed independently of the lenses that will be fitted to the frames. Within reason, lenses are selected according to the required prescription and then ground as necessary to fit the frame. The frame manufacturers know the general properties of the lenses that will be fitted to their frames, but consideration of the specific lenses does not generally occur. Unfortunately, this approach does not facilitate assembly of eyewear with a specific electro-optic lens design, wherein the electro-optic materials may be selected from liquid crystals, electro-chromics, electro-phoretics and the like. Such a lens design dictates certain frame design characteristics. For example, a lens using electro-optic material requires opposed substrates with a controlled gap designed to receive the material. Such a configuration does not allow the lens to be ground arbitrarily to a shape that will fit into an eyewear frame.
Frames generally fall into one of three categories: rimmed, semi-rimless, and rimless. In a rimmed configuration, the lens aperture is completely encircled by the frame. In a semi-rimless configuration, a partial frame carries the lens, although the frame may include a filament which functions to hold the lens in place without providing the appearance of a rim. And in a rimless configuration, the lenses are directly carried by the temples and/or bridge so that no frame encircles the lens or lenses.
The hinges between the temples and the frames may be provided in a number of different constructions. The standard friction hinge is a discrete hinge that attaches the temples and frame front to one another. A spring hinge may also be provided wherein a spring is utilized to bias the connection between the temples and frame front so as to provide a more secure or snug fit on the head of the person wearing the eyewear. An integrated hinge utilizes fingers, or leafs, which are an extension of the respective temples and frame front and wherein a hinge pin is added to connect the fingers and leafs to one another. As mentioned previously, a continuous hinge may be provided wherein the frame front and temples are continuous or integral with one another.
Prior art eyewear utilizes frame rims which are elastically distorted to permit a rigid lens, provided with or without a beveled edge, to be inserted into the frame aperture. Plastic frames are often heated to increase the elasticity of a material so as to allow for the distortion which is relatively small. Metal frames may also be used and often have mechanical joints that are opened to accommodate the rigid lens. It will be appreciated that large deformations are possible with metal frames so as to allow for insertion of appropriate sized lenses.
As noted, attempting to incorporate an electro-optic device into a prior art eyewear frame is problematic. Indeed, given the basic form and construction of a liquid crystal device or any device which uses an electro-optic material that can be used as a lens, special features must be incorporated into an eyeglass frame to accommodate such a lens. As will be understood by a skilled artisan, electro-optic lenses have an edge seal wherein a glue or adhesive bead with different electro-optical properties than the active area—the area containing the electro-optic material—is provided. It will be appreciated that it is desirable to hide the edge seal within the eyewear frame. Moreover, these types of lenses require protruding tabs to serve as electrodes for allowing application of a desired electrical waveform or voltage to the electro-optic material. Accordingly, the lens, the edge seal, and/or the electrode tabs are typically not robust enough to survive insertion into an elastically deformed frame. This is especially true in sunglasses which do not employ a carrier lens. In other words, in generally ophthalmic eyewear applications, a corrective lens is provided which provides a substantial carrier or base to which the liquid crystal device may be attached. As such, the rigidity of the carrier is able to withstand the forces required to insert the lens into the eyewear. However, an electro-optic lens, such as a liquid crystal lens, by itself, cannot withstand such forces. It will further be appreciated that the electro-optic lenses require batteries, drive circuits, switches and other interconnecting conductors for operation. These components must be located somewhere in or on the frame while maintaining an aesthetically pleasing appearance or indeed, be totally unobservable by the wearer or the casual observer.
Based upon the foregoing problems, it will be appreciated that the requirements of both the electro-optic lenses and the supporting components, require that eyeglass frames be more mechanically complex than prior art eyeglass frames regardless of materials used. Distortion of the frames must be accomplished in such a way that the lens or lenses can be inserted into the frame aperture. And it will also be appreciated that elastic distortion of the lens must be avoided so as to ensure the integrity of the lens and the associated electronic components. It is submitted that the known prior art does not address the details of incorporating the lenses, drive circuits, batteries, and interconnections into the frames in an attractive manner. As such there is a need for incorporating the lenses or single lens into rimmed, semi-rimless or rimless design configurations. There is also a need for circuit interconnections, driving circuits, and re-charging devices and related circuits that are adapted for use with electro-optic lenses.